Dose-response study of topical minoxidil in male pattern baldness

Eighty-nine healthy men with male pattern baldness completed a 6-month double-blind, placebo-controlled study of 0.01 %, 0.1 %, 1 %, and 2% topical minoxidil. Subjects on 2% topical minoxidil had a statistically significant increase in mean total target area hair count over baseline compared to the placebo, 0.01%, and 0.1 % topical minoxidil groups (p = 0.04). Changes from baseline were more impressive with the 2% topical minoxidil group but not significantly different from the 1% topical minoxidil group in all parameters of objective response to treatment. The investigator, however, rated more subjects as having at least a moderate cosmetic response to treatment in the 2% versus 1% topical minoxidil treatment group. These results indicate that 1% topical minoxidil is the lowest effective concentration of topical minoxidil for male pattern baldness of those tested. Because of the more impressive changes in hair counts and the cosmetic preference for the 2% versus 1% topical minoxidil, 2% topical minoxidil may be the standard preferred treatment for male pattern baldness. (J Am Acad Dermatol 15:3037, 1986.)